Cellular wireless communication systems support wireless communication services in many populated areas of the world. While cellular wireless communication systems were initially constructed to service voice communications, they are now called upon to support data and video (multimedia) communications as well. The demand for video and data communication services has exploded with the acceptance and widespread use video capable wireless terminals and the Internet. Video and data communications have historically been serviced via wired connections; cellular wireless users now demand that their wireless units also support video and data communications. The demand for wireless communication system video and data communications will only increase with time. Thus, cellular wireless communication systems are currently being created/modified to service these burgeoning demands.
Cellular wireless networks include a “network infrastructure” that wirelessly communicates with wireless terminals within a respective service coverage area. The network infrastructure typically includes a plurality of base stations dispersed throughout the service coverage area, each of which supports wireless communications within a respective cell (or set of sectors). The base stations couple to controllers, with each controller serving a plurality of Node B's. Each controller also typically directly or indirectly couples to the Internet. In the 3rd Generation Partnership Agreement (3GPP) these base stations may be referred to as “Node B's” and the wireless terminals may be referred to as user equipment (UE).
In operation, each Node B communicates with a plurality of wireless UEs operating in its cell/sectors. A controller coupled to the Node B routes voice, video, data or multimedia communications between the MSC and a serving base station. Typically, controllers route data communications between a servicing Node B and a packet data network that may include or couple to the Internet. Transmissions from base stations to wireless terminals are referred to as “forward link” or “downlink” transmissions while transmissions from wireless terminals to base stations are referred to as “reverse link” or “uplink” transmissions. The volume of data transmitted on the forward link typically exceeds the volume of data transmitted on the reverse link. Such is the case because data users typically issue commands to request data from data sources, e.g., web servers, and the web servers provide the data to the wireless terminals. The great number of wireless terminals communicating with a single Node B forces the need to divide the forward and reverse link transmission resources (depending on the specific wireless standards, the resources could be frequency band, time slot, orthogonal code, and transmit power) amongst the various wireless terminals.
Wireless links between base stations and their serviced wireless terminals typically operate according to one (or more) of a plurality of operating standards. These operating standards define the manner in which the wireless link may be allocated, setup, serviced and torn down. One popular cellular standard is the Global System for Mobile telecommunications (GSM) standard. The GSM standard, or simply GSM, is predominant in Europe and is in use around the globe. The GSM standard has evolved in part into the 3rd Generation Partnership Agreement (3GPP). 3GPP provides Technical Specifications and Technical Reports for a 3rd Generation Mobile System based on evolved GSM core networks and the radio access technologies that they support (i.e., UMTS Terrestrial Radio Access (UTRA) both Frequency Division Duplex (FDD) and Time Division Duplex (TDD) modes). The scope also includes the maintenance and development of the Global System for Mobile communication (GSM) Technical Specifications and Technical Reports including evolved radio access technologies (e.g. General Packet Radio Service (GPRS) and Enhanced Data rates for GSM Evolution (EDGE)). While GSM originally serviced only voice communications, it has been modified to also service data communications. General Packet Radio Service (GPRS) operations and the Enhanced Data rates for GSM (or Global) Evolution (EDGE) operations coexist with GSM by sharing the channel bandwidth, slot structure, and slot timing of the GSM standard. GPRS operations and EDGE operations may also serve as migration paths for other standards as well, e.g., IS-136 and Pacific Digital Cellular (PDC). The UMTS technology is an adaptation of the WCDMA 3G system by GSM. One reason for the high data rates that may be achieved by UMTS technology stems from the 5 MHz WCDMA channel bandwidths versus the 200 KHz GSM channel bandwidths. HSDPA technology is an Internet protocol (IP) based service, oriented for data communications, which adapts WCDMA to support data transfer rates on the order of 10 megabits per second (Mbits/s). Developed by the 3G Partnership Project (3GPP) group, the HSDPA technology achieves higher data rates through a plurality of methods. For example, many transmission decisions may be made at the base station level, which is much closer to the user equipment as opposed to being made at a mobile switching center or office. These may include decisions about the scheduling of data to be transmitted, when data is to be retransmitted, and assessments about the quality of the transmission channel. The HSDPA technology may also utilize variable coding rates.
In some instances, HSDPA may provide an improvement in network capacity as well as data speeds higher than those in even the most advanced 3G networks. HSDPA may also shorten the roundtrip time between network and terminal, while reducing variances in downlink transmission delay. These performance advances may translate directly into improved network performance and higher subscriber satisfaction. Since HSDPA is an extension of the GSM family, it also builds directly on the economies of scale offered by the world's most popular mobile technology. HSDPA may offer breakthrough advances in WCDMA network packet data capacity, enhanced spectral and radio access networks (RAN) hardware efficiencies, and streamlined network implementations. Those improvements may directly translate into lower cost-per-bit, faster and more available services, and a network that is positioned to compete more effectively in the data-centric markets of the future.
The capacity, quality and cost/performance advantages of HSDPA yield measurable benefits for network operators, and, in turn, their subscribers. When deployed, HSDPA may co-exist on the same carrier as the current WCDMA Release 99 services, allowing operators to introduce greater capacity and higher data speeds into existing WCDMA networks. Operators may leverage this solution to support a considerably higher number of high data rate users on a single radio carrier. HSDPA makes true mass-market mobile IP multimedia possible and will drive the consumption of data-heavy services while at the same time reducing the cost-per-bit of service delivery, thus boosting both revenue and bottom-line network profits. For data-hungry mobile subscribers, the performance advantages of HSDPA may translate into shorter service response times, less delay and faster perceived connections. Users may also download packet-data over HSDPA while conducting a simultaneous speech call.
HSDPA may provide a number of significant performance improvements when compared to previous or alternative technologies. For example, adaptive modulation/coding of HSDPA data channel (HS-DSCH) based on channel quality feedback information from the UE may be possible. Also, the HS-SCCH power setting may be based on channel quality feedback from the UE. However, implementing advanced wireless technologies such as WCDMA and/or HSDPA may still require overcoming some architectural hurdles because of the very high-speed, wide bandwidth data transfers possible. For example, multiple-input multiple-output (MIMO) antenna architectures, and multipath processing receiver circuitry may be implemented to process the high speed, high bandwidth received RF signals to digital data.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.